This is a multidisciplinary study of stress in diabetic patients. The three aims are to compare coping with psychological stresses (life events) (a) in diabetic and nondiabetic subjects in terms of their symptoms and immune responses, (b) in diabetic patients in terms of whether they have good or poor control of their disease, and (c) in diabetic patients in terms of whether they develop a complication of their disease or not. Subjects will be studied at baseline and every six months for three years. The object is to determine the psychobiological changes in response to stress and particularly its outcome on the course of diabetes. How degree of perceived stress, family support, age, and complicance with medical regimens in diabetic patients effect these outcomes will also be determined.